Flexible corrugated tubular metal wall.



, W. M. FULTON. FLEXIBLE GORRUGATED TUBULAR'METAL WALL.

APPLICATION FILED APR. 30, 1913.

1,094,323. Patented Apr. 21, 1914-.

wi/tmeooao TED jsTATEs PATENT oiiricii.

WESTON M. FULTON, OF KNOXVILLE, TENNESSEE, ASSIGNOR TO TI-IE FULTON COMPANY, OF KNOXVILLE, TENNESSEE, A. CORPORATION 0F MAINE.

FLEXIBLE COIRIRUGrATEID TUBULAR METAL lWALL.

Lcaaaas,

To all whom it may concern:

Be it known that I, WESTON M. FULTON, of Knoxville, Tennessee, have invented a new and useful Improvement in Flexible Corrugated Tubular Metal Walls, which invention is fully set forth in the following specification.

This invention relates to llexible, corrugated tubular metal walls, adapted for making vibratory vessels, llexible pipe connections and the like, as described and illustrated in my U. S. Patents Nos. 887,084; 903,465; 947,229; 967,010; 975,519; 976,060, and 979,460, and to methods of making the same. The object of the invention is to provide flexible corrugated metal walls of the kind referred to, which will better resist at their bends the bending strains to which they are normally subjected, and thereby enable the life of the walls to be prolonged.

The vibratory movement of tubular corrugated metal walls, as heretofore constructed, takes place in large measure in the curved or lbent portions of the wall.

These bends are subjected to flexing back and forth, the radii of curvature varying as the wall extends' or collapses, or is flexed from side to side. Extension of the wall places the layers of metal, on the convex side of the bends, under compression, and on the concave side under tension, and collapsing the wall causes a reverse condition. These portions of the Wall arethereforesubjected to the greatest wear and deterioration. `Repeated bending strains confined to this limited portion of the wallof the vessel or tube, result in time in cracking the Wall where the bends occur, rendering the wall unfit for conlining a fluid and terminating the life of the wall.

My invention overcomes the above objections by providing a corrugated wall so constructed that the strains, heretofore set up in the bends, are transferred in whole or in part from the bends tothe lateral or flat portions connecting the bends of the corrugations. The bending action will then be distributed over a larger area afforded by the flat portions, andthereby relieve the bends, in as great a measure as desired, from wear while increasing the useful flexibility Specification of Letters Patent.

Application led April 30, 1913.

Patented Apr. 21, 1914. Serial No. 764,731.

of the connecting portions of the wall. This result is accomplished by superimposing on the main corrugations of the tubular wall, secondary corrugations which run parallel to the axis of the tubular wall or cross the main corrugations at any desired angle to their planes, thereby stiffening these curved connecting portions with respect to the lateral or flat portions of the wall. This construction throws more of the strain upon the lateral portions, and thereby relieves the curved portions. While I prefer to stiffen in this manner both the inner and outer bends of the corrugations of the tubular wall, I may apply the secondary stilfening corrugations to either the exterior or interior corrugations of the tubular wall, and include either construction within the scope of my invention. In practice, the secondary or stiffening corrugations should preferably not be of such depth as to prevent the flexure of the alternate concave and convex portions of the wall, but they should be sufficient to stiffen these convex and concave portions so that their llexure will be confined within very narrow limits, while the lexure of the lateral connecting port-ions will be greatly increased. The bending strains inthe wall will thus be largely transferred to and distributed in the lateral portions, thereby greatly increasing the durability of the wall. `The secondary or stiffening corrugations may be impressed around the circumference of the curved portions of the corrugations in any suitable manner, such as by means of rolls, the peripheries of which are formed in the shape necessary to secure the requisite result, and may be directed parallel to or at an angle with the longitudinal laxis of the tubular wall. I prefer, however, to make them parallel to the axis.

In order that the invention may be readily understood, reference will be had to the accompanying drawings illustrating one embodiment of the inventive idea, but such drawings are only for the purpose of illustration and to assist the description, and arenot intended to limit the scope of the invention.

Figure 1, is a side elevational view, partly in broken sectior, showing ',a corrugated exible wall provided, with my improvement; Fig. 2, is a plan view, partly in section, showing vthe top or upper end of the wall; Fig. 3, is a broken detail perspective view on an enlarged scale; Figs. 4 and 5, are enlarged sectional detailed views of the wall; and Fig. 6, is a diagrammatic view for comparison.

In Fig. 1, is shown a flexible tubular metal Wall having corrugations consisting of alternate curved or bent portions 1, 2 united by flat portions 3. The surface'of the bends is broken up into a sinuous contour by a series of secondary corrugations 4, the crests and troughs of which cross the bends in the direction of the longitudinal axis of the tubular wall and merge into the fiat portions 3 and into each other by continuous curves, Fig. 2, with a view of avoiding sharp angles which would cause lines of wear and final rupture therein. The depth of these secondary corrugations vary as they lap around the bends, the deepest portions coinciding with the central portions of the bends or where planes normal to the axis of the wall bisect the curved surfaces of the bends. In Fig. 5, this depth is indicated by the distance separating the tangent lines 5, 6. To avoid sharp lines of demarcation where the secondary corrugations joint the flat connecting portions 3, the corrugations 4 are formed shallow and fade out in the surface of the at connecting portions 3. This construction is shown clearly in Figs. 3 and 5. The crest of the secondary corrugation is indicated at 7, and merges into the fiat connecting portion about the points 8, Fig. 5, while the trough of the secondary corrugation extends farther into the portion 3 and fades into its surface, as more clearly shown in Fig. 3, at the locality 9.

The operation of my improved wall may be readily understood by confining attention to the more or less diagrammatic illustration of a single bend of the corrugation constructed according to the principles of my invention, Fig. 4 and comparing the same with a bend made in accordance with the old practice, see Fig. 6. As heretofore constructed, vibratory movements and flexures of the tubular corrugatedwall are accompanied by and largely confined to flexing back and forth of the bends, the curvatures of which vary as their radii lengthen and shorten under the movement of the wall. When the wall collapses into the dotted line position a, Fig. 6, the radius of curvature of the bend shortens, and when the wall extends to the opposite dotted line position b, the radius lengthens. The bending strains in the metal wall are thus localized in the bends, which are called upon to endure the largest part of the wear on the vessel or tubular wall, and are, therefore, the parts which first weaken and give out. In my improvement the small corrugations located crosswise of the bends stiifen the latter and enable them to resist liexing back and forth under the vibratory movements of the vessel. In fact, the bends as thus constructed take little part in the extension and collapsing of the wall. This is illustrated in Fig. 4, which shows the two positions of the wall. In the dotted position a', corresponding to the collapsed condition of the vessel, the bending is shown as taking place in the connecting vportions 3, due to the stiiening action of the small corrugations in the bend which remains practically in its normal curvature. In position which is that of extension of the vessel, the bending action is likewise transferred to the connecting portion 3, while the corrugated bend remains practically unchanged.

It will thus be seen that I have, by my construction, enabled the fiat portions of the corrugations to take the larger part of the bending strains, and relieve to a large extent the bends from wear. Owing to the flowing curves assumed by the Hat connecting portions, during vibratory movements, their radii of curvature are enormously increased over those taking place heretofore in the bends. Disintegration of the wall by repeated flexures is thereby greatly lessened, by flattening the bending angles along the lines of wear, and the life of the vessel is increased.

What I vclaim is l. A vibratory tubular metal wall having corrugations, the bends of which are provided With stiening corrugations parallel to the longitudinal axis of the tubular wall.

2. A vibratory tubular metal wall having corrugations, the bends of which are provided with stiffening corrugations which run crosswise of the bends of the first-named corrugations.

3. A vibratory corrugated tubular metal wall, consisting of alternate concave and convex portions, united by lateral portions, said concave and convex portions being stiifened'. by corrugations passing around the same and extending somewhat into the lateral portions. f

4. A vibratory corrugated tubular metal wall, consisting of alternate concave and convex portions united by lateral portions, said concave and convex portions being stifened by corrugations whose greatest depth is at the point of greatest curvature and which decrease in depthl gradually until they vanish within the lateral portionsl of the wall.

5, A vibratory tubular metal wall having corrugations free from circumferential seams, the bends of which are provided with stli'ening corrugations running crosswise of said first-named corrugations.

6. A vibratory tubular metal Wall free from circumferential seams and having circumferential corrugations provided with superimposed corrugations running cross- Wise of said main corrugations specicaton in the seriblng wltnesses.

WESToN M. FULTON.

Witnesses.:

H. S. MGCOY,A I. A. MARTIN. 

